Fluid Mosaic Model of cell membrane Flashcards
What is the first function for cell membranes?
= barriers
What is the second function for cell membranes?
= seperate one part of an organelle from another part
What is the third function for cell membranes?
= location for chemical reactions
What is the fourth function of cell membranes?
= involved in cell signalling
What can easily pass through the cell membrane?
= contains hydrophobic centre (non-polar), hydrophobic molecules can easily pass
= prevents hydrophilic (polar) molecules from easily passing through
Can water molecules pass through the cell membrane?
= Yes
= extremly small
= slow rate
What is a cell surface membrane based on?
= phospholipid bilayer
What great number of molecules does a cell surface membrane contain?
= protein molecules
= some are only one side of the membrane- other span the membrane
=
What else does the cell surface membrane contain and what is it’s structure?
= Cholesterol
= polar hydrophilic group at one end
= group can attract the polar head groups on the phospholipid molecules
= rest is non-polar+ hydrophobic
= attracts the non-polar fatty acids
= invreases strength of surface membrane + more stable
What does cholesterol reduce?
= reduces sideways movement of phospholipids + other molecules in membrane
= helps control fluidity of membrane
= prevents membrane from becoming too fluid under warm condition and too rigid in cool conditions
What does packing the spaces between phospholipids do?
= chlosterol helps to reduce the movement of water soluable chemicals across the cell membrane
WHat does it mean by fluid in the fluid mosaic model?
= Fluid: phospholipid molecules can move around each layer- membrane is flexible + change shape
What does it mean by mosaic in the fluid mosaic model?
= membrane is studded with protein molecules
= arrangement of these protein varies
